Key Distribution Schemes for Channel Protection on Pay-TV Systems

• Main Authors: Wang, Jian-Chyuan, 王堅權
• Other Authors: Shiuh-Pyng Shieh
• Format: Others
• Language: zh-TW
• Published: 1998
• Online Access: http://ndltd.ncl.edu.tw/handle/32704947905354975861

碩士 === 國立交通大學 === 資訊工程學系 === 86 === A Pay-TV system is a commercial TV system, which charges its subscribers for receiving the TV programs. The purpose of channel protection is to insure that only the authorized subscribers, who have paid the fee, can watch the TV programs, while an unauthorized viewer can see nothing intelligible. In many real systems, TV programs are scrambled before broadcasting, and only the authorized subscribers will get the keys to descramble the original TV programs correctly. For higher security consideration, thekeys should be updated constantly. It is a very inefficient way to send the updated keys to each subscriber respectively. In this thesis, we proposed three key distribution schemes for different situations in order to efficiently and securely distribute the keys to the authorized subscribers. In these schemes, only one or two messages are transmitted for updating the keys, and only simple computation functions, i.e. the symmetric key encryption/ decryption function, the one-way function and the XOR function, are adopted for implementation in the smart card-based systems.